Lately I was “playing around” with POM (Parallay Occlusion Mapping) Materials for 3D Skidmarks for our vehicles. The POM Material works fine for Static Meshes, but when used in a Deferred Decal Actor, the Rotation has to be (0,-90,0), otherwise the Texture (Material) gets stretched and the POM effect disappears. Hard to describe how it deforms, it has no clearly recognizeable pattern, but it seems that the Parralax Occlusion assumes a different viewing angle than it actually is.
My question is what could cause this and how would I fix it. For a better understanding of the problem, here a few pictures of the Material itself and the working POM on Static Meshes and the POM on Deferred Decals, one in the default Rotation (0,-90,0), and one with modified rotation.
The working POM Decal on the Landscape, not rotated (Default Rotation is applied: 0,-90,0)
The POM Material
When Rotated, the POM effect doesnt work anymore, the texture looks distorted
The effect increses with wider angles (more rotation)
On Static Meshes it works fine (the rotation)